Determine the number of students who are graduating. For example, a school has 2,000 graduates.
Determine the number of students who entered the school as freshmen, then add students who transferred to the school and subtract students who transferred out of the school. In our example, the freshmen class which is graduating started with 2,050 students, had 11 students transfer in and 12 students transfer out. Therefore, there were 2049 students in the graduating class.
Divide the number of students graduating by the number of students in the graduating class. In the example, 2,000 students divided by 2049 students equals 0.976 or 97.6 percent.